Heat exchange apparatus



Dec. 30, 1941. E. R. WALKER ,2

HEAT EXCHANGE APPARATUS Filed June 28, 1940 5 Sheets-Sheet l INVENTOREdmund 7i? Ma l/(er ATTORRE Dec. 30, 1941. E. R. WALKER HEAT EXCHANGEAPPARATUS Filed June 28, 1940 5 Sheets-Sheet 2 W ATTOR INVENTOR EdmundIt? h d/ker Dec. 30, 1941. E. R. WALKER HEAT EXCHANGE APPARATUS FiledJune 28, i940 3 Sheets-Sheet 3 INVENTOR t'amunafi Walker- ATTO PatentedDec. 30, 1941 UNITED STATES PATENT. OFFICE HEAT EXCHANGE APPARATUSEdmund E. Walker, Kenmore, N. 1., usiznor to Fcdders ManufacturingCompany, Inc., Bufialo,

Application June 28, 1940, Serial No. 342,892 3 Claims. (Cl. 257-136)visedv to support the coil unit in such manner that the coil may freelyexpand or contract in its normal plane, and yet be fullyprotectedagainst all other physically or thermally activated strains.The residual stresses, which may be caused by differential expansion orcontrac= tion within the heating surfaces of the coil unit, areautomatically absorbed by the structure of the tube components thereof,which are devised to yield individually by bending to'accommodatethemselves to the'position oi the remainder of their companion tubeswithout the application of direct thrust or tension loads on any portionof the structure.

Other features of the invention, including a novel steam distributionsystem, are more specif-= ically set forth in the accompanyingspecifics. tion and drawings, wherein:

Fig. 1 is a front View of the coil unit;

Fig. 2 is an enlarged section on the line 2-2 of Fig. l, with the lowerportion shown in elevation;

Fig. 3 is an enlarged fragmentary section on the line 3-45 oi Fig. 2;

i is a perspective view showing the orifice structure oi the upperextremity of the tubes;

Fig. 5 is a diagrammatic view showing several oi the units applied to aportion 0! an air heating system. I

The invention consists of a rigid fabricated casing it which serves tosupport and contain a coil unit i I. The casing H is formed or sheetmetal parts, including top and bottom sections it and. E5, and sides N,The sides II are formed with marginal flanges I! and II, the latter orhorizontal flanges supporting the sections H and it which are securedthereto by rivets 2 l' (Fig. 3). it will be seen in Fig. 2 that thesections it and it are provided with flanges Ho and lie, and

with ofiset central portions h and lit, respectlvely, which latterportions serve to partially enclose the headers oi the coil unit it, aswill be explained hereinafter.

Theflangeslla, lie, and it, it will he noted. all lie in a common plane,and thus they pro vide a continuous marginal pad P on each face of thecasing, to which other casings may be secured, or to which a duct 2| anda blower casing 2| may be attached, as shown diagrammatically in Fig. 5.Holes 22 are provided in the pads P at spaced intervals to receive boltsor rivets for securing the casing 'to such other units.

It will also be observed that at the corners of the pads P theextremities of the flanges a, Na are slightly ofiset, as indicated bythe numere-ls 24, to receive cars 25 on the flanges II. Rivets 26 securethe parts together at these points. I

On the sides of the casing, the exposed ends oi the top and bottomsections H and i5 are covered by angle members 28, which members aresecured to the horizontal flanges l8 of the sides M3 by rivets 2d.

The coil unit it consists of upper and lower cylindrical headers 35 and36, and connecting finned tubes 3'8. The headers are closed at eachextremity by heads 38, which are soldered in place. Each head 3i: isformed with a projecting mounting pintle so. The extremities of thetubes ill are entered in internally flanged holes M and G2 in theheaders 35 and 86 respectively, and it will be seen in Fig. 4 that theextremities of the tubes, which lie within the header 36, are formedwith rounded and reduced terminals 48 formed with angularly spaced ports45 partially definedv by intermediate and opposing jaws 48.

The tubes 3? are bent near their central portlon, as indicated by thenumeral M, so that individual tubes may respond to expansion orcontraction by arching between the supports provided by the headers 35and 36.

The upper or steam header 35, at its center portion, carries hrackets 48which are rigidly connected to the top section l4 oi the casing byrivets 4| (Figs. 3 and 3). The upper portion through clearance holes 53in the sides l6, and

they enter bearings 54 of externally located brackets 55, which bracketsare rigidly secured to the sides it by rivets 58 and El.

A distributor plate 58 is secured within the header 35 immediatelybeneath the steam inlet nipple t0, and it is formed with two curvedopinlets of the tubes.

they are received in brackets 60. The brackets 60 are similar to thebrackets 55, except that they are formed with vertical slots SI forreceiving the ends of the pintles I 01 the lower header 3. The lowerheader 35 carries an integral outlet nipple 62, which projects throughan opening 53 in the bottom section 15.

, Bent plates 64 and 85 are secured to the upper and lower sections I4and i5, where they serve as shrouds to direct the air in a smooth flowthrough the finned tube portion of the coil unit.

In a heating installation, it will first be ob-' served that the centralsupports 48 of the upper the header pintles 50 in the bearings 54permits only axial movement of the ends of the headers,

and warping or twisting effects are thus pre-- vented.

It will be apparent that since the upper header 35 is fixed axially,expansion of the tubes 31 will'cause free downward movement of the lowerheader 36 under the sole guidance of the pintles 4|! thereof in thevertical slots 6| of the brackets ill. Thus, the lower header 361s freeat all times to accommodate itself to the dimensional changes of thetubes 37, as may be occasioned by thermal conditions within the coilunit.

In view of the fact that under unusual operating conditions differentialexpansion or contraction may occur between the various tubes 31,provision is made in the knee or bent portion I! of each tube, so thateach tube is in efiect an eccentric column which may bend or warpbetween the headers. Thus, the lower header may, as previously noted,move in response to the expansive demands of a majority of the tubes,and at the same time the remainder of the tubes, even though expandingat a different rate or degree, will accommodate themselves automaticallyto the general movement without placing disruptive strains on theirconnection joints with the headers.

such ports and the-surrounding structure serve as scale breakers,wherein, when a scale is lodged over one or the ports, it finds littlesupport on the non-planar edges thereof, and therefore the scale will besubjected to a violent fluttering action resulting in its disintegrationor dislodgment.

In addition, the ports I! also serve as entrance nozzles for each of thetubes 31, having slightly restrictive characteristics, which isdesirable to insure uniform steam distribution to all of thetubes.

It will be understood by those skilled in the art that the example ofthe invention as above described is intended to disclose certain inven-It will now be apparent that the structure of the casing is such that itserves as a rigid housing within which the coil unit is supported, sothat it is free to expand in its normal or natural plane withoutrestraint, but is rigidly protected against all twisting or warpingaction.

Referring to the operation of the unit, it will be seen in Fig. 5 thatsteam is supplied through the supply pipes S for distribution throughthe units ll. Air is drawn through the units by the blowerunit 2 l, andthe heated air is directed to its destination, not shown herein. As isunavoidable in such systems, boiler scales are entrained with the steam,and often the scales are of suiiicient size to block or partially blockthe In the present structure, the orifice ports 45 are not onlydifficult to block, because of their partially spherical contour, but

tive principles, which are obviously applicable to numerous other typesof heat exchange devices. It is therefore intended that the inventionshall be deemed commensurate with the scope of the following claims.

I claim: 1. In a heating device, a casing, a heating unit within saidcasing, said unit including spaced upper and lower headers and tubesconnecting said headers, means connecting the upper header to the casingand including a rigid connection between the central portion of theupper header and the casing, said upper header having a projectingpintle on each extremity, brackets secured to opposite sides of thecasing and having bearings formed therein for slidably receiving saidpintles, whereby the ends of the upper header are permitted freeexpanding movement under axial guidance of said, pintle and bearingconnections, and cooperating means on the lower header and casing forpermitting free guided movement of the lower header.

2. In a heating device, a casing, a heating unit within the casing, saidunit including spaced upper and lower cylindrical headers and paralleltubes connecting the headers, said casing having offset recessedportions for partially receiving said headers, cylindrical pintlesprojecting from the ends of both headers, bearings on the casing forslidably and rotatably receiving the pintles of the upper header, saidcasing also having vertically slotted members for receiving the pintlesof the lower header.

3. In a heat exchange device, a substantially rectilinear casing havingtop, bottom, and side walls connected together, a heating member mountedin said casing, said member comprising upper and lower headers andinterconnecting expansible tubes, each of said headers being providedwith end plates having a pintle projecting therefrom, opposed bracketssecured to the casing adjacent the ends of the upper header but spacedtherefrom, said brackets being formed with cylindrical bearingsreceiving the upper header pintles with longitudinal clearance, wherebythe upper header mayexpand in an axial direction, and opposed slotsformed in said casing adjacent the lower header, said slots receivingthe lower header pintles for vertical and axial expansion of saidheader, said expansible tubes being bent whereby expansion of theheating member as a Whole may be accommodated by extension of said tubesand movement of said lower header with respect to said slots.

EDMUND R. WALKER.

